Introduction to Yuxi: Yuxi, formerly known as Ranxi, also known as Ranxi, is the last tributary of Xiaoshui. After Liu Zongyuan moved to Yuxi, he changed the name of Ranxi or Ranxi to Yuxi, and named the small spring in the northeast as Yuquan, which means that his own stupidity extends to Yuxiquan. He also wrote "Preface to Yuxi Poems" and "Foolishness". "River Dull", to relieve the injustice accumulated in the heart, and to laugh at the political experience of being convicted of stupidity. Later generations also used Yuxi to refer to Liu Zongyuan.